Season 2 saw the departure of Dr. Beverly Crusher to head Starfleet Medical and her subsequent replacement by Dr. Katherine Pulaski. A number of stories focus on the development of Data, introducing him to his "grandfather," revealing his interest in Sherlock Holmes, determining his status as a living being, and revealing to him the moral implications of the Prime Directive. He also clashes several times with Dr. Pulaski, who does not initially regard him as a living being.

Commander William T. Riker is also a focus of this season, settling his differences with his estranged father, deciding to give up an offer for his own command so that he can remain on the USS Enterprise-D, becoming the first Starfleet officer to serve on a Klingon vessel, and nearly dying after becoming infected by a deadly alien parasite.

Lieutenant, J.G. Worf becomes chief of security and meets his mate, K'Ehleyr, and their son, Alexander, is conceived. Geordi La Forge is promoted to full Lieutenant and becomes Chief Engineer. Guinan comes on board the Enterprise-D to serve as bartender in Ten Forward, and significantly, Q introduces the crew of the Enterprise-D to the Borg, their most dangerous adversary yet.

Additionally, as a result of budget overruns in earlier episodes, the finale episode "Shades of Gray" was required by Paramount to have a three-day shoot to recover costs. As a result, the episode was written as a 'clip show,' and was composed chiefly of clips from the previous 47 episodes. (Captains' Logs: The Unauthorized Complete Trek Voyages)

Star Trek V: The Final Frontier was filmed and released during the run of this season. It was the first time a Star Trek feature film was shot simultaneously with a television series on adjoining sound stages. The same was true of every subsequent Star Trek film up to and including Star Trek Nemesis.

In the second season, Lieutenant, J.G. Worf serves as permanent chief security officer, begins wearing a gold uniform, and transfers from Emergency Manual Override aft bridge station to the tactical station. His rank is still Lieutenant Junior Grade and he will not be promoted to full Lieutenant until the beginning of season 3. Actor Michael Dorn now has a different prosthetic forehead and different sash as part of his costume for Worf. Also, La Forge is promoted to full Lieutenant and chief engineer during the break between seasons 1 and 2 and begins wearing a gold uniform in "The Child". The Ten Forward set appears with Whoopi Goldberg in the recurring role of Guinan; Riker starts wearing a beard; also, during this season, Diana Muldaur as Dr. Katherine Pulaski replaces Gates McFadden as Dr. Beverly Crusher. Out of all seven seasons of The Next Generation, this is the only one in which Gates McFadden does not appear, other than through "flashback" footage from Season 1 in "Shades of Gray".

Guest star Diana Muldaur is generally considered a regular cast member, as her character appears in all but two episodes and otherwise fulfills the role of a main character. The actress was reportedly offered a place in the opening credit sequence, but declined and was listed instead as a Special Guest star. (Star Trek: The Next Generation Companion)

During the hiatus between the first two seasons, which was longer than a usual hiatus due to the writer's strike, Frakes grew a beard, mainly because he dislikes shaving. According to the Trek: The Next Generation Crew Book, Roddenberry liked it-- Frakes recalled at a convention that Roddenberry said it had an appropriately "nautical" look-- and the beard became a permanent part of Riker's character. The executives had some reservations, however. As Frakes tells it, they told him to shave off "eighteen percent" of the beard! The only explanation behind a number of such bizarre precision is that each executive chose a percentage (ten, twenty, twenty-five, etc.) and the average number was chosen. Frakes would not be seen beardless again until Star Trek: Insurrection; additionally, he was seen wearing only a circle beard or moutee (a type of goatee) in DS9: "Defiant". "Growing the beard" has since become a term for when a show turns "good" (a reverse of "jumping the shark"), in reference to this. [1]

The Enterprise bridge set was modified for the second season. The access panels in the port and starboard sections of the main bridge changed colors from red to grey. These panels would look the same for the rest of the series, with the exception of alternate timelines. In addition, Picard's chair was modified, with the panels on the armrests permanently opened, and the two additional small seats added on the sides of Riker's and Troi's chairs were modified. The conn and ops station chairs are replaced with new swiveling chairs. Some of the aft computer terminals were reassigned. Worf's previous station "Emergency Manual Override" and "Environment" are now maintained under the names "Mission Operations" and "Engineering."

A new sickbay set was constructed featuring portions of the set from the first season combined with a new intensive care ward, freeing up the portion of the set that also doubled as the observation lounge.

Ron Jones ("Where Silence Has Lease", "The Outrageous Okona"-"Loud As A Whisper", A Matter Of Honor", "The Royale", "The Icarus Factor", "Q Who", "Up The Long Ladder", "The Emissary", "Shades of Gray")

Merri D. Howard ("Where Silence Has Lease", "The Outrageous Okona"-"Loud As A Whisper", "A Matter Of Honor", "The Dauphin", "The Royale", "The Icarus Factor", "Q Who", "Up The Long Ladder", "The Emissary", "Shades of Gray")

Dan Curry ("Where Silence Has Lease", "The Outrageous Okona"-"Loud As A Whisper", "A Matter Of Honor", "The Dauphin", "The Royale", "The Icarus Factor", "Q Who", "Up The Long Ladder", "The Emissary", "Shades of Gray")

Alan Sims ("Where Silence Has Lease", "The Outrageous Okona"-"Loud As A Whisper", "A Matter Of Honor", "The Dauphin", "The Royale", "The Icarus Factor", "Q Who", "Up The Long Ladder", "The Emissary", "Shades of Gray")